Field coil



Dec. 19, 1933. o. F. FREELAND FIELD COIL Filed Sept. 15, 1931 INVENTOJROrville [Heel BY g %(444 ATTORNEYS 9 Hw- M a 2 n 1 (H mmHw\\\\\\\\\\\\\.

Patented Dec. 19, 1933 PATENT OFFICE FIELD COIL Orville F. Freeland,Muskegon, Mich., assignor to Anaconda Wire and Cable Company, New York,N. Y., a corporation of Delaware Application September 16, 1931 SerialNo. 563,130

3 Claims.

This invention relates to electric coils and more particularly to fieldcoils.

One of the objects of the present invention is to provide an improvedfield coil product. 6 Another object is to provide improved means foranchoring the coil leads.

Other objects and advantages will become apparent as the invention ismore fully disclosed.

In accordance with the objects of this inven- 10tion I have devised anovel lead anchoring means and a novel coil assembly which is clearlyset forth in the accompanying drawing, wherein Fig. 1 is a perspectiveview of the completed coil of the present invention;

Fig. 2 is the same with the cover partly removed illustrating the leadanchoring means of the present invention;

Fig. 3 is a side elevation sectional view of the coil illustrating theelements of the coil assembly; and

Fig. 4 is an enlarged section of upper portion of coil. g

Referring to the drawing, the usual field coil 5 comprises a number ofturns of copper wire 1 usually of exceedingly small gauge and coatedwith dielectric insulating material; wound about a tubular core 2 andretained in position thereon by side walls 3. Heretofore it has been 3.customary to comprise the tubular core 2 and side walls 3 of a unitaryassembly commonly identified as a spool. When the desired number-ofturns of wire are wound upon the spool,

the entire assembly is then wrapped or enclosed in dielectric insulatingmaterial, the two ends of the copper wire only extending therefrom. Oneof the difliculties heretofore experienced has been in providing meansto bring out the inner end of the coil without short circuiting the sameto the remaining turns. Another difficulty is to provide means to anchorthe fine gauged wire of the coil ends to the lead wires so that they arenot subjected to tensional stresses or strains when in service.

.45 In the present invention I have overcome these two difficulties andothers bycomprising the spool of two sections, a tubular core 2 and sidewalls 3. Side walls 3 are comprised of two sections, an inner windingwasher 4 and an outer end cap 5. The inner winding washer 4 is adaptedby means of segments 6 to be frictionally attached to the end of thetubular core 2 in the manner shown. The inner end of the copper coil isbrought through the spool assembly at this junction in the mannerindicated in Fig. 2. When the desired number of turns have been wound onthe core the two ends of the coil are anchored to lead wires '1' and 8.

In accordance with the present invention the lead wires are anchored inthe following manner. A flexible piece of leatheroid 12 is wound aboutthe outside of the coil and two copper tabs 9 and 10 are attachedthereto in any convenient manner or position; such as by inserting thesame through slits in the leatheroid and doubling back as illustrated inFig. 2. The ends of the coil are attached to the under section of thetabs 9 and 10, and the ends of lead wires 7 and 8 are attached to theupper section. The under section of the tab is insulated from the coilsurface in any convenient manner such as by doubling over the leatheroidas shown. Preferably the tabs 9 and 10 are positioned as indicated sothat the leads may be extended from one end of the coil in relativelyclose relationship.

End caps 5 comprised of dielectric material adapted to retain theleatheroid in position are then placed on the coil and a suitableflexible dielectric strip 11 wound about the outside 80. thereof andcemented thereto serving thereby to retain all the elements together intheir assembled position. The entire coil may then be dipped, sprayed orpainted with any suitable or desired electrically insulating, water andoil proofing composition.

The particular lead anchoring means I have provided permits theapplication of considerable tensional stresses and strains to the leadwires without the application of any strain upon the coil ends. Theparticular assembly of parts permits the rapid assembly of the coil, andprovides a neat and finished appearance to the coil not heretoforeobtainable.

There may be many modifications and adaptations made of the presentinvention without departing essentially from the nature and scopethereof as may be set forth in the following claims:

What I claim is:

l. A field coil comprising a tubular core and demountable end washersunited thereto, a wire coil wound about said coil, a flexible dielectricstrip member having a pair of metal tabs extending therethrough, thecoil ends being attached to the under portion of the tab and lead wiresattached to the upper section thereof, end cap members adapted toenclose the coil ends and to extend over the flexible strip member toretain said member in position upon the outer-1. 9

periphery of the coil, and an outer flexible strip member wound aboutthe outer. periphery of the coil and adapted to be attached to the. capand first strip member to form a unitary structure.

member wound about the outer periphery of the I coil and adapted to beattached to the cap and first strip member to form a unitary structureand an exterior dielectric, water and oil insulating coating thereover.

Y ;3. In a field coil, a coil comprised of a plurality of turns of wirewound about a core, coil terminals and anchor means therefor, saidanchor means comprising a flexible strip member comprised of dielectricinsulating material, metal tab members attached to said strip memberwith a section thereof extending through the said strip, the coilterminals being attached to the under section of said tab, and leadwires to carry the current to said coil terminals attached to the uppersection of said tab.

ORVILLE F. FREELAND.

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